Third party styluses (styli?) have a history of being useless. I have bought and tested (then relegated to a drawer) most of them. Any third party stylus will have to make serious use of the enhanced scanning speed of the pro, because that seems to me to be crucial. I'm not sure if the iPad Pro also has a finer set of capacitor sensor grid points or not. But I am banking on the Apple Pencil, though I do hope some SERIOUS third party (ie, not Adonit, et al!) will study the iPad Pro hardware carefully and try to improve on the Apple Pencil (though I don't know yet how good the latter is! But better is always desirable).